Gearman vs Mosca: What are the differences?

What is Gearman? A generic application framework to farm out work to other machines or processes. Gearman allows you to do work in parallel, to load balance processing, and to call functions between languages. It can be used in a variety of applications, from high-availability web sites to the transport of database replication events.

What is Mosca? A Node.js MQTT broker. A Node.js MQTT broker, which can be used as a Standalone Service or embedded in another Node.js application.

Gearman and Mosca can be primarily classified as "Message Queue" tools.

Some of the features offered by Gearman are:

• Open Source It’s free! (in both meanings of the word) Gearman has an active open source community that is easy to get involved with if you need help or want to contribute. Worried about licensing? Gearman is BSD
• Multi-language - There are interfaces for a number of languages, and this list is growing. You also have the option to write heterogeneous applications with clients submitting work in one language and workers performing that work in another
• Flexible - You are not tied to any specific design pattern. You can quickly put together distributed applications using any model you choose, one of those options being Map/Reduce

On the other hand, Mosca provides the following key features:

• MQTT 3.1 and 3.1.1 compliant
• QoS 0 and QoS 1
• Various storage options for QoS 1 offline packets, and subscriptions

Mosca is an open source tool with 2.84K GitHub stars and 501 GitHub forks. Here's a link to Mosca's open source repository on GitHub.